1. Field of the Invention
The present invention is generally related to the field of drilling oil and gas wells, and, more particularly, to a method and apparatus for cementing a branch well from a parent well.
2. Description of the Related Art
There are a variety of techniques for drilling multiple branch wells from a parent well. One technique for drilling such wells is disclosed in U.S. Pat. No. 6,056,059 that issued May 2, 2000, entitled xe2x80x9cApparatus and Method for Establishing Branch Wells From A Patent Well.xe2x80x9d Generally, that patent discloses a multiple branching sub that includes a branching chamber and a plurality of branching outlets. During the construction of the branching sub, the branching outlets are formed into non-circular shapes such that all of the branching outlets fit within a cylindrical shape that is coaxial with and has substantially the same diameter as the branching chamber. After the branching sub is deployed downhole through the parent casing of the well, an expansion tool is lowered into the interior of the branching sub. The expansion tool is, thereafter, actuated to expand the previously deformed branching outlets into substantially circular outlets.
The next operation to be performed is the cementing of the branching chamber and branching outlets into the well bore. However, given the fact that, prior to expansion, the branch outlets were in a non-circular form, e.g., concave or convex, a traditional float shoe valve could not be positioned within the non-circular, deformed branch outlets prior to the insertion of the branching sub into the well. That is, cementing of the branching chamber and the branching outlets could not be accomplished with a conventional float shoe valve. Thus, there is a need in the industry for a method and apparatus for cementing branch wells from a parent well.
The present invention is directed to a method and apparatus that solves or reduces some or all of the aforementioned problems.
One embodiment of the present invention is directed to a cementing valve comprised of a valve body and a moveable member, each of which have outlets through which cement can flow. The moveable member is positionable between a first open position and a second closed position where the outlets of the valve body and the moveable member are aligned and not aligned, respectively. At least one of the valve body or the moveable member is adapted for releasable coupling to a cementing stinger.
The cementing valve can further comprise a compression seal pack that is attached to the valve body. A latch can be coupled to one of the valve body or moveable member, the latch adapted for retaining the cementing valve downhole after completion of the cementing operations. One or more collapsible anti-rotation devices can be attached to the cementing valve. The valve body, the moveable member, or both can be adapted for releasable coupling to the cementing stinger. The releasable coupling can be one or more shear elements. The cementing valve can further comprise a retaining latch that, when actuated, secures the moveable valve member in its second, closed position.
The moveable member can be positioned within the valve body and can be adapted for translational or rotational movement relative to the valve body.
Another embodiment of the invention is a cementing valve comprising a valve body having an outlet and a moveable member positioned within the valve body. The moveable member also has an outlet and is positionable to an open position when the moveable member outlet is aligned with the valve body outlet and to a closed position when the moveable member outlet is not aligned with the valve body outlet. Both the valve body and the moveable member are adapted for releasable coupling to a cementing stinger. A latch is coupled to one of the valve body or moveable member and a retaining latch is coupled to the moveable member that, when actuated, secures the moveable member into its closed position. The latch can be adapted for retaining the cementing valve downhole after completion of cementing operations.
The cementing valve can further comprise a compression seal pack that is attached to the valve body. The latch that is coupled to one of the valve body or moveable member is adapted for retaining the cementing valve downhole after completion of the cementing operations. One or more collapsible anti-rotation devices can be attached to the cementing valve. The moveable member can be positioned within the valve body and can be adapted for translational movement relative to the valve body or for rotational movement relative to the valve body.
Yet another embodiment of the present invention is a method for cementing branch wells from a parent well. The method comprises releasably coupling a cementing valve to a cementing stinger, positioning the cementing valve in a branch well outlet and cementing the branch well outlet into position. The method further comprises actuating the cementing valve to a closed position after completion of cementing operations, and decoupling the cementing stinger from the cementing valve.
The act of releasably coupling the cementing valve to a cementing stinger can further comprise positioning the valve to an open position. Positioning the cementing valve in a branch well outlet can further comprise running the cementing valve downhole on the cementing stinger and can include actuating a latch to secure the cementing valve into position so that cementing operations can begin. The step of cementing the branch well outlet into position can further comprise pumping cement through the cementing stinger and the cementing valve to an area adjacent to the branch well outlet.
Actuating the cementing valve to a closed position can comprise positioning the moveable member relative to the valve body. The act of decoupling the cementing valve from the cementing stinger can comprise raising the cementing stinger a first distance to decouple a portion of the cementing valve and raising the cementing stinger a second distance to completely decouple the cementing valve from the cementing stinger.
Still another embodiment of the invention is a method for cementing a branch well that comprises releasably coupling a cementing valve to a cementing stinger, the cementing valve being in an open position, running the cementing valve downhole on the cementing stinger until the cementing valve is positioned within a branch well outlet, and pumping cement through the cementing stinger and the cementing valve into an area adjacent to the branch well outlet. The method further comprises positioning a moveable member of the cementing valve to a closed position and decoupling the cementing stinger from the cementing valve.
The decoupling of the cementing valve from the cementing stinger can comprise raising the cementing stinger a first distance to decouple the cementing stinger from either a valve body or a moveable member of the cementing valve and raising the cementing stinger a second distance to decouple either the valve body or the moveable member that was not decoupled in the movement of the cementing stinger a first distance. The act of running the cementing valve downhole can further comprise actuating a latch to secure the cementing valve into a position whereby cementing operations can begin. Positioning the moveable member of the cementing valve to a closed position can comprise translational movement or rotational movement of the moveable member relative to the valve body of the cementing valve.